Over the last few years, ABug have hosted a fascinating series of talks over Zoom on a wide range of retro Acorn and BBC Micro topics. We posted about a few of them last Christmas.
 
Just in time for this Christmas, ABug have been busy over the last few weeks posting some more of the talks to their YouTube channel, just in time for escaping from another load of Christmas film repeats on TV.
 
This time around, there's talks on a variety of topics, including building RISC OS 3.71 from its original source code, software presevation and rescuing data from old BBC Micro discs, stories from BBC Micro developers and more.
 
The full list of videos is on the ABug YouTube page (with more still to come in the coming days!), but here's a few of our favourites to get you started:
 

RPCEmu is a really important piece of software to me because it allows me to turn my laptop into a RISC OS machine when I am away from home. It provides an almost complete RISC OS machine under emulation for Linux, Mac and Windows. It can run the latest RISC OS 5.28 as well as 'classic' versions. There are several Easy-Start bundles with all you need to setup RPCEmu for RISC OS. The website states the software is alpha quality, but I have found it very stable in daily use.
 

Archimedes emulator Arculator has been updated to version 2.1 with some very nice new features. The emulator can now emulate an A4 laptop or the A500 prototype and can also emulate more podules, including the Aleph One 386 and 486 podule, meaning you can now run DOS and Windows in the emulator.
 
Other podules now supported include Acorn ROM podules, MIDI podules, Oak SCSI interfaces and Computer Concepts' ColourCard. Support for disc images in the .hfe format is also now included.
 
  
 
Head over to the Arculator website to download the new version.
 

What better way to spend your free time this Christmas while we're not allowed to go anywhere than to sit back, relax and enjoy some interesting presentations on a variety of Acorn and RISC OS topics?
 
Since 2014, ABug - the Acorn and BBC Micro User Group - have been holding regular events featuring talks on a wide range of topics relating to Acorn and RISC OS computers, both as in-person events and more recently as virtual events. We've selected a few of our favourites in this article, but the ABug website has a lot more talks available to choose from.
 

In previous articles, I looked at VirtualRPC as a way to run RISC OS on my Mac. Another options is RPCEmu.
 
This offers 2 potential main advantages over Virtual Acorn - it is free and it runs RISC OS 5.
 
The software can be downloaded from http://www.marutan.net/rpcemu/ and you can also get a USB drive with the software on it from RISC OS Open.
 
RPCEmu is available for Mac, Linux and Windows. The Windows and Mac versions both come as ready to run applications while Linux needs you to build the source code (which is also supplied). This is because it needs the Allegro Game Library. This process is not as daunting as it sounds and the instructions are clear and cover each step. If you are already a Linux user, you may already be doing this,. If you are not it is a really good introduction to compiling software which will open lots of new software to you....
 
The Mac version of RPCEmu has some isses with Retina screens on the later Macs (it works fine if you move it onto an external monitor). You can get around running this by running the software in low resolution (Menu and Info options). This trick does not appear to work on the 2016 October MacBookPros :-(
 
RPCEmu allows you to configure the software and choose settings like mouse buttons, etc. A copy of RISC OS 5 is included and a Hard drive to setup a basic RISC OS 5 installation.
 
This gives you a fully-functional RISC OS 5 machine, which can access the local hard drive. I have a shared directory on my setup so I can have a single shared copy of my RISC OS applications between Virtual Acorn and RPCEm. (You cannot share everything because RISC OS 5 and 6 have different setups and !Boot drives but it it useful to be able to shared data and third party software.) In usage I find RPCEmu runs slightly slower than Virtual Acorn but the speed is perfectly acceptable on a high end machine.
 
So if you are looking for an easy way to run RISC OS on your non-RISC OS machine, or even something to improve your Linux skills, have a look at RPCEmu.
 
RPCEmu website
 

In Part2 of our speed comparison, I wondered whether there would be a signficant change to the figures from Emulation if we tried a different processor or screen resolution. So in Part 3, let us see...
 
1680 x 1050 in 32M, 32K and 256 colours for test 4
Processor - Looped instructions (cache)
489562 275% 480160 269% 502375 282%
Memory - Multiple register transfer
8569 5289% 8349 5153% 8828 5449%
Rectangle Copy - Graphics acceleration test
2842 1174% 5033 2079% 8751 3616%
Icon Plotting - 16 colour sprite with mask
23098 1154% 19288 964% 23032 1151%
Draw Path - Stroke narrow line
4950 317% 5209 333% 5309 340%
Draw Fill - Plot filled shape
5533 379% 6111 418% 6814 467%
HD Read - Block load 8MB file
586290 19660% 616427 20671% 618415 20738%
HD Write - Block save 8MB file
554164 18223% 502875 16536% 535318 17603%
FS Read - Byte stream file in
2613 1262% 2678 1293% 2681 1295%
FS Write - Byte stream file out
1188 618% 1190 619% 1190 619%
 
It looks like Retangle Copy is significantly faster in 32K mode compared to 16M but otherwise we see little advantage on these tests (remember we get slightly different results every time we run the tests so we should not be concerned at small differences).
 
710 ARM versus StrongArm Processor emulation
Processor - Looped instructions (cache)
501300 281% 498030 279%
Memory - Multiple register transfer
8916 5503% 8723 5384%
Rectangle Copy - Graphics acceleration test
2776 1147% 2726 1126%
Icon Plotting - 16 colour sprite with mask
23293 1164% 24660 1233%
Draw Path - Stroke narrow line
5196 333% 4969 318%
Draw Fill - Plot filled shape
5633 386% 5684 389%
HD Read - Block load 8MB file
583984 19583% 583984 19583%
HD Write - Block save 8MB file
510986 16803% 546133 17958%
FS Read - Byte stream file in
2687 1298% 2643 1276%
FS Write - Byte stream file out
1165 606% 1187 618%
 
So it looks like if your usage is similar to that measured in these tests, there is not a significant difference running on MacPro. As we suggested last time, this is a valid test but it may not be a fair comparison for your usage. And it only looks at raw speed not other factors which may be important to you such as power usage (Titanium easily wins), portability (you will want a laptop and should be comparing PiTop versus Mac) or ability to run macOS, Linux, Windows (MacPro is only contender).
 
There are other settings in the VirtualAcorn configuration file (VA.cfg) which may also be worth experimenting with. So what is your personal experience? And what settings are you tweaking for maximum performance on your Mac or Windows box?
 

In part 1 we outline our plans to pit a Titanium (running RISC OS 5) against VirtualRPC (running RISC OS 6) on the latest MacBookPro laptop. Here are the scores, Titanium first each time.
 
Titanium versus VirtualRPC
 
Processor - Looped instructions (cache)
3762909 2115%, 524989 295%
Memory - Multiple register transfer
27373 16896%, 9184 5669%
Rectangle Copy - Graphics acceleration test
3253 1344%, 3067 1267%
Icon Plotting - 16 colour sprite with mask
42279 2113%, 26035 1301%
Draw Path - Stroke narrow line
11622 745%, 5337 342%
Draw Fill - Plot filled shape
17204 1179%, 6021 412%
HD Read - Block load 8MB file
115924 3887%, 608316 20399%
HD Write - Block save 8MB file
84216 2769%, 530070 17430%
FS Read - Byte stream file in
2493 1204%, 2634 1272%
FS Write - Byte stream file out
2553 1329%, 1170 609%
 
The 2.9gig Intel processor is not quick enough as an emulator to outperform a 1.5gig ARM chip on the Titanium but they said the new Macs have very fast SSD drives and that gives the Emulator an edge on block filesystem operations. You can compare these figures with those on Chris Hall's website (and try the tests yourself).
 
Does RISC OS performance on the MacBookPro vary if you run fullscreen or from battery?
 
A second question I posed last time was whether there would be any changes. Let us run it 3 times (in a window, in fullscreen mode and in fullscreen mode unplugged to see)...
 
Processor - Looped instructions (cache)
525238 295%, 522668 293%, 522822 293%
Memory - Multiple register transfer
9090 5611%, 9370 5783%, 9160 5654%
Rectangle Copy - Graphics acceleration test
2947 1217%, 2913 1203%, 2899 1197%
Icon Plotting - 16 colour sprite with mask
20316 1015%, 20308 1015%, 24903 1245%
Draw Path - Stroke narrow line
5396 345%, 5531 354%, 5457 349%
Draw Fill - Plot filled shape
5994 410%, 6098 417%, 6045 414%
HD Read - Block load 8MB file
592095 19855%, 559651 18767%, 567762 19039%
HD Write - Block save 8MB file
481882 15846%, 527207 17336%, 522039 17166%
FS Read - Byte stream file in
2593 1252%, 2657 1283%, 2653 1281%
FS Write - Byte stream file out
1141 594%, 1168 608%, 1192 620%
 
So no notable differences between modes.
 
Conclusions
This article was partly intended as a bit of Christmas entertainment and the advantages will vary with your exact usage or requirements (the Mac laptop does use a lot more power for example, whereas the VirtualRPC solutions does provide a 'free' Apple Mac as part of the package). And you could always run Jeffrey Lee's excellent VNC server with the free VNC viewer built into the Mac as another combination.
 
Is this a fair test? Mazzeo's Law says that the answer to any big question is 'It all depends'. It will not give a true answer for every single use case but I would argue that it is a 'valid' test in that it makes a reasonable and repeatable comparison. The Acorn Emulator offers several different chip emulations (700,7500, StrongArm) and may well be better suited to colour modes with less than 16M colours. Stay tuned for Part 3 which will see if these result in a faster Acorn experience (or feel free to test yourself)...
 
My main conclusion is that both my systems offer a very viable RISC OS solution which allows me to use my favourite operating system at home (my Titanium) or on the move (my laptop).
 
And in the future...
I generally replace my work Mac every 2-3 years and the rumour mills like to speculate that Apple may move to ARM chips in the future. At the moment, Apple uses Intel chips, and you can currently use a program called BootCamp to intall Windows directly onto Apple Laptops. Commerial software from VMware, and Parallels, and the free VirtualBox allow you to create virtual machines using the Intel hardware. This is much faster as it does not have to emulate another chip. Running RISC OS on a high end ARM laptop with a solution like this would be very appealing....
 

This old chestnut has been around for many years now, and I think it always will be. But Christmas is a time for chestnuts, so let us see if we can put a new Iconbar spin on it by comparing the latest Apple and Elesar hardware for a 2016/7 take on the question....
 
I have both a shiny new TiMachine (using the Titanium motherboard) and a snazzy new MacBookPro on my desk which I am going to pit against each other. This article is split into 2 parts. In part 1, I am going to explain all the details and part 2 will give you the actual results.
 
RISC OS on native ARM hardware
ARM options have exploded in the last few years and you now have a wide range of machines on which RISC OS can be run directly (RapberryPi, Pandaboard, ARMX6, IPEGv5, Titanium). Exact performance will vary between machines and also depend on the type of disk you have (SD card, Zip drive, SSD drive).
 
If you are upgrading from a RISC PC or Iyonix, all of them will give you a welcome speed boost. I have several RaspberryPis, a Panda and a TiMachine and they all provide solid platforms for running RISC OS.
 
RISC OS on a MacBookPro
The latest version of the high end Apple laptop was released in October 2016. They added some additional features to excite/annoy you (touch sensitive screen to replace function keys, only USB-C sockets). The current machines use Intel processors (Skylake release) with fast RAM and SSD drives. So RISC OS is run using an emulator program (running on macOS) which converts ARM code into Intel code. There are ways to speed this up, but it is slower than it would be if running on ARM directly. The critical question is whether the faster speed of the Intel processor can compensate for the extra work involved.
 
If you want to run RISC OS on Mac you have a choice of the commercial VirtualRPC (which runs RISC OS 4/6) and the free RPCEmu (runs RISC OS 5). Both programs emulate a complete RISC OS machine (either running full-screen or in a Window) which can also access the macOS filing system. I find VirtualRPC to be faster in my tasks so I will be using that for this comparison.
 
How to compare?
We are going you use the benchmark program ROMark which you can find on Chris Hall's excellent website, where he has lots of data on performance for different machine running RISC OS. Any benchmark is going to be a proxy because everyone will use their machines in different ways and it does not include details which may be important (such as power usage, budget, need for speed, personal sentiment, etc). VirtualRPC cannot do 1920x1200pixels in 16 million colours, so we will use 1680x1050pixels in all tests to provide a common reference. The tests give very slightly different results on each run but are reasonably close each time.
 
It does give us a fairly good proxy for comparing different machines in a reasonably consistent way. It will also allow us to look at several options, particularly on the MacBookPro. Is RISC OS faster in full-screen or window mode? What happens if we are on batter power? We will be finding out...
 
See you in Part 2 for some numbers. Anyone prepared to make any bets?